I have tried to look up and find the errors I've been having.

The one I have right now is this

2021-08-12 02:52:15,910 main WARN Advanced terminal features are not available in this environment
←[32m[02:52:16] [main/INFO] [cp.mo.mo.Launcher/MODLAUNCHER]: ModLauncher running: args [--gameDir, ., --launchTarget, fmlserver, --fml.forgeVersion, 31.2.55, --fml.mcpVersion, 20200515.085601, --fml.mcVersion, 1.15.2, --fml.forgeGroup, net.minecraftforge]
←[m←[32m[02:52:16] [main/INFO] [cp.mo.mo.Launcher/MODLAUNCHER]: ModLauncher 5.1.2+70+master.2845bb9 starting: java version 16.0.2 by Oracle Corporation
←[m←[32m[02:52:16] [main/INFO] [ne.mi.fm.lo.FixSSL/CORE]: Added Lets Encrypt root certificates as additional trust
←[m←[32m[02:52:16] [main/INFO] [mixin/]: SpongePowered MIXIN Subsystem Version=0.8.2 Source=file:/D:/Minecraft/Servers/1.15.2%20Server/libraries/org/spongepowered/mixin/0.8.2/mixin-0.8.2.jar Service=ModLauncher Env=SERVER
←[mException in thread "main" ←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]: java.lang.NoClassDefFoundError: jdk/nashorn/api/scripting/NashornScriptEngineFactory
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at net.minecraftforge.coremod.CoreModEngine.loadCoreMod(CoreModEngine.java:48)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at net.minecraftforge.coremod.CoreModProvider.addCoreMod(CoreModProvider.java:12)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:762)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:276)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at net.minecraftforge.fml.loading.LoadingModList.addCoreMods(LoadingModList.java:88)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at net.minecraftforge.fml.loading.moddiscovery.ModDiscoverer.discoverMods(ModDiscoverer.java:125)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at net.minecraftforge.fml.loading.FMLLoader.beginModScan(FMLLoader.java:213)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at net.minecraftforge.fml.loading.FMLServiceProvider.runScan(FMLServiceProvider.java:107)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at cpw.mods.modlauncher.TransformationServiceDecorator.runScan(TransformationServiceDecorator.java:111)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at cpw.mods.modlauncher.TransformationServicesHandler.lambda$runScanningTransformationServices$8(TransformationServicesHandler.java:115)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:273)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.HashMap$ValueSpliterator.forEachRemaining(HashMap.java:1766)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:913)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at cpw.mods.modlauncher.TransformationServicesHandler.runScanningTransformationServices(TransformationServicesHandler.java:116)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at cpw.mods.modlauncher.TransformationServicesHandler.initializeTransformationServices(TransformationServicesHandler.java:63)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at cpw.mods.modlauncher.Launcher.run(Launcher.java:75)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at cpw.mods.modlauncher.Launcher.main(Launcher.java:65)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at net.minecraftforge.server.ServerMain$Runner.runLauncher(ServerMain.java:63)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at net.minecraftforge.server.ServerMain$Runner.access$100(ServerMain.java:60)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1069]:       at net.minecraftforge.server.ServerMain.main(ServerMain.java:57)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1078]: Caused by: java.lang.ClassNotFoundException: jdk.nashorn.api.scripting.NashornScriptEngineFactory
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1078]:       at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:636)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1078]:       at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:182)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1078]:       at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:519)
←[m←[32m[02:52:16] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1078]:       ... 35 more
←[m

 

If someone can at least direct me to a post that fixes this issue that would be amazing. I'm starting to get a little frustrated

minecraft 1.15 requires java 8-15, you currently using java 16
downgrade your java to 8-15 and the problem should be fixed

I have tried to launch it with java 15 and it just stopped working

how did you change the java version

I made it run with java under the java 15 folder

 

I selected things after it stopped stopped working. I have run a server before with no issue and it all of a sudden stopped working. 

This is what it ends up doing

I am running the batch file. This is what is in the batch file

java -jar forge-1.15.2.jar
pause

I've also tried 

java -Xmx4096M -Xms4096M -jar server.jar nogui
pause

run the command line in the console and post output

Both of them have the save result as if it ignored them both

Thank you very much for helping with this. I dont know how my java files got screwed up so much but that fixed them. My server is now working, you da best guys